WordPress – Access php variables from another file within an html file

I have a page with several tabs and to keep things organized I have one file for the overall page template and one for each tab that will be opened. When pressing the tabs I hide/unhide (with the class hidden which sets display: none) sections which is originally placed like this in my page_template.php file:

<div id="content-wrapper">
    <section id="page_tab_1">
        <?php get_template_part( 'page/page_tab_1' ); ?>
    </section>
    <section id="page_tab_2" class="hidden">
        <?php get_template_part( 'page/page_tab_2' ); ?>
    </section>
</div>

Now I want to use a variable in both page_template.php and page_tab_1.php. When placing $my_variable = 'Test'; at the top of the page_template.php I can of course use it below with e.g. <?php echo $my_variable; ?>, but when I try to echo it in page_tab_1.php it doesn’t work.

I solved it by adding functions at the top of page_template.php like this:

function get_my_variable(){return 'Test';}

Then I can use the following code in both files:

$my_variable = get_my_variable();

The reason I don’t want to put $my_variable = 'Test'; in both files is because some of the real variables take some calculations and I don’t want to duplicate too much code.

Question

I thought I could just declare the variables at the top of page_template.php since the other code is pasted below that, but I guess that is not how get_template_part works. So is there a more elegant/smart way to declare variables in page_template.php which can then be used by all page_tab_x.php files?

>Solution :

get_template_part let you pass additional arguments to the template through the third parameter $args.

@see https://developer.wordpress.org/reference/functions/get_template_part/

get_template_part(
    'template-part',
    'name',
    array(
        'key1'  => $myValue1,
        'key2'  => 'myValue2',
    )
);